I finished Season 1 and marginally enjoyed it. Still have goodwill for John Krasinski, but I wasn't as impressed with the show as i had hoped I'd be. It's well done, but as others have said, it doesn't seem particularly groundbreaking.
I think you must be right. The actor that played the husband role in the casino scene is Lee Tergesen, whom you might remember as Tobias Beecher in Oz, among many other shows. It would seem strange to hire him for this role, only for it to be a cameo. Makes you feel that he'll make a reappearance at some point. Plus, we know that someone was pulling Suileman's strings and helping with financing and stuff, yet the show never really dealt with that aspect. I thought it was strange that Ryan & Greer split town for Russia without following that up. Maybe the two things are connected.